USB: usb-serial: replace shutdown with disconnect, release

This patch (as1254) splits up the shutdown method of usb_serial_driver
into a disconnect and a release method.

The problem is that the usb-serial core was calling shutdown during
disconnect handling, but drivers didn't expect it to be called until
after all the open file references had been closed.  The result was an
oops when the close method tried to use memory that had been
deallocated by shutdown.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 37 insertions, 5 deletions

diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 5fe9fe3d..c40f95c 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -2633,16 +2633,16 @@ error:
 }
 
 /****************************************************************************
- * mos7840_shutdown
+ * mos7840_disconnect
  *	This function is called whenever the device is removed from the usb bus.
  ****************************************************************************/
 
-static void mos7840_shutdown(struct usb_serial *serial)
+static void mos7840_disconnect(struct usb_serial *serial)
 {
 	int i;
 	unsigned long flags;
 	struct moschip_port *mos7840_port;
-	dbg("%s", " shutdown :entering..........");
+	dbg("%s", " disconnect :entering..........");
 
 	if (!serial) {
 		dbg("%s", "Invalid Handler");
@@ -2662,11 +2662,42 @@ static void mos7840_shutdown(struct usb_serial *serial)
 			mos7840_port->zombie = 1;
 			spin_unlock_irqrestore(&mos7840_port->pool_lock, flags);
 			usb_kill_urb(mos7840_port->control_urb);
+		}
+	}
+
+	dbg("%s", "Thank u :: ");
+
+}
+
+/****************************************************************************
+ * mos7840_release
+ *	This function is called when the usb_serial structure is freed.
+ ****************************************************************************/
+
+static void mos7840_release(struct usb_serial *serial)
+{
+	int i;
+	struct moschip_port *mos7840_port;
+	dbg("%s", " release :entering..........");
+
+	if (!serial) {
+		dbg("%s", "Invalid Handler");
+		return;
+	}
+
+	/* check for the ports to be closed,close the ports and disconnect */
+
+	/* free private structure allocated for serial port  *
+	 * stop reads and writes on all ports                */
+
+	for (i = 0; i < serial->num_ports; ++i) {
+		mos7840_port = mos7840_get_port_private(serial->port[i]);
+		dbg("mos7840_port %d = %p", i, mos7840_port);
+		if (mos7840_port) {
 			kfree(mos7840_port->ctrl_buf);
 			kfree(mos7840_port->dr);
 			kfree(mos7840_port);
 		}
-		mos7840_set_port_private(serial->port[i], NULL);
 	}
 
 	dbg("%s", "Thank u :: ");
@@ -2707,7 +2738,8 @@ static struct usb_serial_driver moschip7840_4port_device = {
 	.tiocmget = mos7840_tiocmget,
 	.tiocmset = mos7840_tiocmset,
 	.attach = mos7840_startup,
-	.shutdown = mos7840_shutdown,
+	.disconnect = mos7840_disconnect,
+	.release = mos7840_release,
 	.read_bulk_callback = mos7840_bulk_in_callback,
 	.read_int_callback = mos7840_interrupt_callback,
 };